“It’s very exciting,” said Bert Jacobs, co-founder of the Life is Good apparel company. “Dave Matthews can go anywhere he wants. I think he’s casting a vote in our direction and saying, ‘I like what you guys are about.”

Although the musical line-up grabs attention, Jacobs emphasizes that the music is primarily a vehicle to raise funds for his company’s charitable organziation, Life is Good Playmakers.

“The musicians are the hook, but we’ve made a real concerted effort to say it’s a fundraiser first and a concert second,” said Jacobs, who donates all proceeds to train professionals in play therapy to help children affected by poverty, violence and illness. More than 3,500 people have worked with 209,000 children across the country.

As a fundraiser, the festival promotes the company’s message of optimism. It’s not a Pollyanna view that everything is fine, but that people can improve the lives of others and have a good time, Jacobs said. It’s expressed in the musicians selected.

“We’ve chosen musicians who don’t just have talent, but who have depth and celebrate life and its challenges and overcoming adversity,” Jacobs said.

On Sunday, Dave Matthews performs with Tim Reynolds, his collaborator on three double CDs, including “Live In Las Vegas,” which debuted in 2010 at No. 1 on Billboard’s Top Modern Rock/Alternative Albums and Top Rock Albums charts.

“It’s an acoustic set; a little bit more like a storytellers acoustic lab,” said festival director James MacDonald, a 1993 Braintree High School graduate.

In addition to pop star and American Idol judge Sara Bareilles and the buoyant rock band Michael Franti and Spearhead, Saturday performers are singer/song writer Eric Hutchinson, as well as Soul Live, Allen Stone, The Ryan Montbleau Band, Katie Herzig, Muck And The Mires.

Page 2 of 3 - “We love that someone might come to see Sara Bareilles, but leave a fan of one of these other acts,” McDonald said.

In a departure from the two previous years, main stage billing goes to a children’s group, The Fresh Beat Band, known to millions from the Nickelodeon television show.

“The Fresh Beat Band is really having its moment,” McDonald said. “They have a fairly complex stage setup and we want their fans to have ample room to spread out.”

The children’s program, which is the same for both days, features Dan Zanes and Friends, The KIDZ BOP Kids and Josh & the Jamtones.

On the 42-acre Prowse Farm site, the festival has plenty of room for the games and activities that reinforce its focus on play and fun. There’s disc golf, flag football, old-fashioned games, parachute play and a giant collaborative tile mural.

This year, more ticket holders than ever have taken on the role of philanthropists. They raise funds from supporters, just as they would if they were doing a charity walk or bike, and the most successful get perks. Anyone who raises $500 or more gets access to a hospitality area and closer seating; $1,000 or more gets meetings and private performances with musicians.

The majority of money raised is not from the 15,000 tickets sold each day, but from individual fundraising, corporate donations and Life is Good merchandise sales.

“We’re moving in the right direction,” Jacobs said. “We’re not sure how much we will raise, but we are confident we will beat our record. Our goal is that eventually every person who attends will raise funds.”

Reflecting on the third collaboration with Superfly Presents (producers of Bonnaroo), McDonland said Life is Good has surprised skeptics.

“When we first did this, some concert promoters thought we were crazy, that we should do either an adult or a kids festival,” he said. “But great music, backyard games and philanthropy can include everyone.”

Page 3 of 3 - The Life is Good Festival is 11 a.m. - 9 p.m. Saturday and Sunday at Prowse Farm in Canton.

Adults tickets are $65 for Saturday, sold out for Sunday, and $120 for Saturday and Sunday; children’s tickets are $25 for Saturday and sold out for Sunday. Prices increase by $5 for a single day and $10 for two days on Sept. 19.

Shuttles run from free parking at the Route 128/University Avenue Amtrak Station and office park lots on Royal Street in Canton. For information, go to www.lifeisgood.com.